Enteric viruses are responsible for about 67% of foodborne diseases in the US, and are increasingly recognized as important threats to public health. Recently, Noroviruses (NoVs) have become the number one virus involved in foodborne outbreaks. Other important foodborne viruses include hepatitis A viruses (HAVs) and rotaviruses (RVs). Methodologies for the isolation and detection of these viruses from foods lag severely behind their bacterial counterparts. Most contaminated foods contain few viral particles and viruses cannot grow outside of their host; viruses must therefore be concentrated from foods prior to detection. Existing isolation procedures are lengthy, technically difficult to perform, not universally applicable to food matrices, and can damage the integrity of virus particles. Currently, viral nucleic acid amplification by RT-PCR is the most widely used method for virus detection. The development of a universal, rapid and easy-to-use method for the isolation and identification of foodborne viruses is important to ensure the safety of the Ontario food supply. This would reduce the time and cost required for sample analysis by allowing laboratories to adopt a single, simple method. This study aims to develop a rapid and universal viral concentration method, coupled to a DNA microarray platform for simultaneous identification and genotyping. Virus concentration from foods will be achieved using the Pathatrix system. Multiplex PCR will be standardized for the amplification of all viruses of interest and the Norochip (OMAFRA 2003-2005) will be expanded to allow identification and genotyping of HAV, ADV and RV. This universal approach to the identification and characterization of foodborne viruses will allow for quicker response to potential contamination events, more informed control efforts, and better risk assessment and policy-making decisions to control the spread of foodborne viral diseases.
Expected Impact of Project Outcomes on Food Safety in Ontario:
A recent study in the Hamilton region estimates the cost burden of gastrointestinal disease at CDN$115 per person per year, or over $1.4 billion dollars annually for the province of Ontario. Viral agents are responsible for a large percentage of this gastrointestinal disease. While epidemiological data implicate food as a major vehicle of virus transmission, our ability to rapidly and accurately detect viruses in food remains limited. As a result, the source and epidemiology of viral outbreaks cannot always be pinpointed and reported. Our goal is to develop the Pathatrix system into a universal method for the isolation of foodborne viruses from different food matrices and to expand the DNA microarray method pioneered in our laboratory for detecting norovirus. We will integrate virus capture technology into the existing protocol and improve our microarray design to allow detection and typing of additional foodborne viruses. This will result in a standardized two-step system for the isolation, detection and simultaneous genotyping of norovirus, rotavirus, hepatitis A virus and other enteric viruses. This system will generate a single protocol to screen for multiple virus types, saving time and money over current methods which lack standardization and may not be applicable to different types of foods or viruses. The development of this detection system should provide Ontario with the best and latest technology to screen for viruses in foods, thus improving detection and assessment of viral contamination of food and water in Ontario. The epidemiological data obtained from virus typing will be useful in future risk assessment studies. These tools should provide us with the means to improve the quality and safety of foods in Ontario.<P> For more information, please visit the <a href="http://www.omafra.gov.on.ca/english/research/foodsafety/index.html" target="_blank">Ontario Ministry of Agriculture, Food & Rural Affairs (OMAFRA) Food Safety Research Program</a>.